U.S. Patent Publication 2005/0289585 describes a TV system wherein the equalizer parameters and automatic gain control (AGC) gain settings for receiver amplifiers are used to characterize a particular television receiver installation. Once this installation is characterized, the system operator can use, for example, a set of equalizer parameters and/or amplifier gain settings to determine whether the receiver (e.g., a set top box) has been relocated so as to receive content in an unauthorized manner.